1. Field of Invention
The present invention generally relates to a memory technology. More particularly, the present invention relates to non-volatile magnetic memory.
2. Description of Related Art
Computers and other digital systems use memory to store programs and data. A common form of memory is random access memory (RAM). Many memory devices, such as dynamic random access memory (DRAM) and static random access memory (SRAM) devices are volatile memories. A volatile memory loses its data when power is removed.
In contrast to the potential loss of data encountered in volatile memory devices, nonvolatile memory devices retain data for long periods of time when power is removed. Examples of nonvolatile memory devices include read only memory (ROM), programmable read only memory (PROM), erasable PROM (EPROM) and the like.
An alternative memory device is known as magnetoresistive random access memory (MRAM). An MRAM device uses magnetic orientations to retain data in its memory cells. There are at least three different types of MRAM devices, wherein one of them is giant magneto-resisitance (GMR) MRAM device.
During the conventional process of a GMR MRAM device, a GMR magnetic layer is formed between an underlying dielectric layer and an overlying dielectric layer only in partial area. In other partial areas of the GMR MRAM device, deep vias or plugs must electrically connect an overlying conductive layer formed above the overlying dielectric layer and an underlying conductive layer formed under the underlying dielectric layer. High contact resistance is formed between these two conductive layers due to deep vias or plugs.